The present invention relates to an actuator apparatus using a piezo or other smart material and having mountable arms that enable customization of the apparatus for different applications. Smart material actuators are known in the art. However, such devices are generally produced in a relatively limited set of fixed sizes and configurations. The present invention corrects these shortcomings by providing an actuator apparatus that enables attachment of arms of different sizes and configurations, thereby enabling a common set of parts to be assembled into different configurations of smart material actuators, customized to suit the demands of different applications. Having options for customizable arms also allows tuning of the resonant frequency of the actuator, thereby allowing for further flexibility in matching actuators to specific applications.